Microfilm camera



Dec. 11, 1951 E. BERLANT 2,578,037

MICROF'ILM CAMERA Filed May 17, 1947 5 Sheets-Sheet l EMMAA/UEL 559L411;

I N VEN TOR.

Dec. 11, 1951 E. BERLANT MICROFILM CAMERA 5 Sheets-Sheet 2 Filed May 17 1947 Arron/54 Dec. 11, 1951 E. BERLANT MICROFILM CAMERA 5 Sheets-Sheet 4 Filed May 17, 1947 r al Emu/W051. .BEPLAMT;

INVENTOR.

Dec. 11, 1951 BERLANTY 2,578,037

MICROFILM CAMERA Filed May 17, 1947 5 Sheets-Sheet 5 EMMA'A/UEL 552.444,

INVENTOR.

arraew-x AK 3 Mi kg wv mwm Patented Dec. 11, 1951 MICROFILM CAMERA Emmanuel Berlant, Culver City, Calif., assignor to Berlant Associates, Los Angeles, Calif., a

partnership Application May 17, 1947, Serial No. 748,735

3 Claims.

The invention relates to a micro-film camera, and more particularly to a continuous flow camera for copying or photographing a master such as documents or the like onto film. The master is photographed in reduced size on the film, the ratio of reduction being the same as the speed ratio of the master and the film. Micro-film cameras of this general type are wellknown and have a number of defects which are overcome by the improvements constituting the present invention.

With the prior type of micro-film camera, use has been made of a clutch. between the motor and the drum which carries the master, with a finger riding on the drum in the path of the master so as to operate the clutch and drive the film through the camera when the master is on the drum in a position to be photographed. This has the disadvantage that if the master is tissue or very thin: paper, the drum finger may tear it or serve to catch a portion of the paper and prevent it from lying smooth on the drum. This disadvantage is overcome by the present invention which has for an object to control the clutch without mechanical contact with the master. This is accomplished by providing a light sensitive device to control the clutch, the light sensitive device having a light path which is intercepted by the master. Preferably this control is in the form of a bridge circuit having light sensitive cells in two arms of the bridge, the current from the cells being balanced when the master is absent and unbalanced when the master is in position to be photographed, this balance and unbalance controlling a relay which operates the clutch. Preferably both photo-cells are energized from the same lamp or lamps employed for illuminating the master.

Concerning another feature of the invention, lenses of commercial quality have a plus or minus 2% tolerance as to their focal length. It is necessary that the ratio of the front and back focal lengths of the camera lens, i. e., objective lens, should be the same as the speed ratio of the master and the negative film in the camera. While some means have been used heretofore to equalize these two ratios, they are somewhat complicated and it is a further object of the present invention to provide a simpler means for this purpose. This is accomplished by permitting the position of the objective lens to remain fixed, while providing a simple means to adjust each of the front and back focal lengths.

A further object of the invention is to provide an improved film magazine having the film supply and take-up elements and a driving sprocket and with a drive element readily coupled to or uncoupled from the motor drive by inserting the magazine into or removing it from its casing. Preferably the casin has a stop to fix the back focal length, and this stop being adjustable so that in the course of manufacturing and testing the camera, the necessary adjustment can be made in the back focal length to accommodate a particular objective lens.

A further object is to provide a number of signal lamps showing the proper functionin of the camera and its associated parts, and one of these lamps may serve to show that the supply reel is empty, this condition also operating the clutch to stop the camera.

It will be apparent that the invention provides a compact device which is simple to operate, as well as a number of other features and improvements as set forth in the specification and claims.

For further details of the invention, reference may be made to the drawings wherein Fig. 1 is a vertical sectional view of a micro-film camera according to the present invention.

Fig. 2 is a sectional view on the broken line 2-2 of Fig. 1 looking in the direction of the arrows.

Fig. 3 is a sectional view taken on line 3-3 of Fig. 2 looking in the direction of the arrows.

Fig. 4 is a sectional view on line 44 of Fig. 2 looking in the direction of the arrows, parts being broken away.

Fig. 5 is a front view in elevation as seen on line 55 of Fig. 4 lookin in the direction of the arrows.

Figs. 6 and 7 are enlarged sectional views on lines of the corresponding numbers in Fig. 1 lookin in the direction of the arrows.

Fig. 8 is a front view in elevation.

Fig. 9 is a diagram of the circuit for controlling the electrical apparatus of micro-film camera.

Referring in detail to the drawings, as shown in Figs. 1 and 8, the micro-film camera I comprises a main casing 2 having a protruding lower front portion 3 having a top wall e to serve as a shelf to guide the master 5, such as a paper document or the like, into an elongated inlet slot 6, to feed the master to the master drum 1. The front 3 has an upright wall 8 having a. discharge outlet 9 for the master.

Above the master drum 1, at the front of the main casing 2 is a compartment Ill in which the film magazine I removable fits. Access is had to the film magazine II by opening a door 12 at the front of the compartment I9.

The door I2 has a window |3 for an indicator I4 to show how much, if any, film remains on the supply spool l5. The indicator I4 is at the front end of a follower lever I59 pivoted as indicated at I5. The other end of the follower lever I59 has a roller I! which rides on the supply spool I5.

Between the lower end of door I2 and the inlet 5, the front wall portion I8 of the main casing is provided with a window I9 for inspecting a footage counter 29 which may be calibrated in terms of the number of sprocket holes in the film passing the recording slit 2| at the rear of the magazine II.

The rear wall 22 of compartment I9 has a sleeve 23 in which fits the lens tube 24 of a suitable objective lens schematically indicated at 25. The lens tube 24 is held in sleeve 23 by a screw 29. Lens 25 has a diaphragm 27 having an adjusting ring |2l which extends through an opening 28 in the top cover 29, being provided with a pointer indicated at 39 for calibrations in terms of the stop opening as usual.

As shown in Fig. 2, the motor 3| is arranged outside of the side wall 32 of the main casing 2, and provided with a cover 33.

Outside of the other side wall 34 of the main casing 2 is arranged a clutch 35 as well as the vacuum tubes 56, 31, 39, and relay 39 of the circuit shown in Fig. 9. The tubes 35, 31, and 38 are supported on the upper portion and relay 39 on the lower portion of an U channel 49 serving as' a double shelf suitably secured to the side wall 34 by bolts or rivets such as indicated at 4|. The clutch 35 and its associated power drive elements later described, and the tubes 35 to 38 and relay 39 are enclosed in a removable cover 42 held in place by screws or bolts as indicated at 43, around its rim 44, as shown in Figs. 2 and 3.

As shown in Fig. 8, at each side of the door I2 is a panel, suitably supported on the front wall I9 of the main casing 2, one of these panels being indicated at 45 having a green lamp 45 and a main line switch 41, the other panel 48 having a red lamp 49 and a switch 59 to momentarily operate the solenoid 5|, see Fig. 3, of the clutch 35, to bring unexposed film in front of recording slot 2| at the start.

The above will give a general idea of the arrangement and operation of the parts which will now be described in further detail.

Power drive.The master drum 1 is driven by a rubber or friction roll 52 on a shaft 53 arranged behind the drum 1 as shown in Fig. 1, shaft 53 extending beyond the opposite side walls 34 and 32 as shown in Fig. 2. Shaft 53 is supported in suitable bearings indicated at 54 and 55. One end of shaft 53 is coupled through gears 56 to motor 3|. The other end of shaft 53 is coupled through gears 51, see also Fig. 3, to a shaft 58 supported in a bearing 59 on the outside of wall 34. Shaft 59 at its upper end has a gear 69 in mesh with two planetary gears 5| and 52 mounted on a disk 53 loosely mounted on shaft 64. Fixed to shaft 64 is a gear 95 also in mesh with the planetary gears 6| and 92. Disk 53 has notches in its periphery and shaft 94 has a disk 61 of the same diameter fixed thereon and having similar notches 68 in its periphery. The notches 95 or 58 are engaged by a detent 59 on the plunger 19 of solenoid 5|. Plunger I9 is held up by spring II when solenoid 5| is Clo-energized,

with detent 69 engaging a notch 58 to hold shaft 54 stationary and prevent the feeding of film in magazine II. At this time, if the motor is running, shaft 58 rotates and disk 63 rotates around shaft 54 without rotating shaft 54. When solenoid 5| is energized, detent 99 moves to release notch 58 and engage one of the notches 55 whereby shaft 58 drives shaft 64 through the gears 59, 5|, 92 and 65. Shaft 64 is supported by a bearing 12 on the outside of wall 34 and at its upper end is coupled through a worm gear 73 to shaft 74, see Fig. 2. Shaft 14 is mounted in a bearing 15 on the side wall 34. Intermediate the ends of shaft I4 is bevel gear I5, see also Fig. 5, coupled with other gears indicated at I! and I8, to the film counter 29. The inner end of shaft 14 projects through the side wall I of the magazine compartment I9 where it has a spur gear 78, in position to be engaged on one side thereof by the spur gear l9 on the copy drum 89 which also has sprocket teeth 8| to drive the film, and on the other side thereof by an idler gear 82 meshing with gear 83 on the take-up spindle 84, see Figs. 1, 2 and 4. The take-up spindle 94 and the supply spindle 85 are rotatably mounted in the side walls of the magazine II and the gears 79, 82 and 83 are carried by the magazine II on its outside wall 85. The gears I9 and 82 on the magazine II are engageable with or disengageable from the driven gear I8 in the compartment I9, by simply pushing magazine II into or pulling it out from compartment I9. To guide such movement of magazine II it may have a dovetail slide connection 91 with the bottom of compartment I9. The speed ratio of the copy drum 59 and the master drum I is the same as the ratio of the back and front focal lengths of lens 25 and this ratio is also the same as the ratio of the width of recording slit 2| to the ex posure slit 88 at drum 1; all of such ratios for example may be 20 to 1.

Film magaeine.The film magazine II can be loaded or unloaded by removing its side wall 89 which is held in place by screws 99, see Figs. 1 and 2. The compartment I9 is braced by a cross piece 9| suitably fastened to the opposite walls 32 and 34 and is also supported by a corner brace 92 shown in Figs. 1 and 4.

Master drum-The master drum 1 comprises a cylinder 93 of glass, plastic or other translucent material, secured to end rings 94 and 95. End ring 95 is rotatably carried by a metal tube 96 coaxial with the cylinder 93. Tube 95- is removably supported at its right end as shown in Fig. 2 in a ring 97 having a flange 98 at the outside wall 32 and to which it is removably secured by means such as bolts 99. Tube 95 at its other end is welded or otherwise secured to flange I99 on a ring |9I having a cylindrical bearing I92 rotatably supporting the ring 94 on the drum I. Ring |9| has an outer flange I93 removably secured by means such as bolts I94 to a ring I95 and to the outside of the wall 34. Ring |9| and tube 95 can be withdrawn to the left, from casing 2 when bolts I94 are removed as the right end of tube 95 will slide out of ring 91 and as the opening in ring I95 is of larger diameter than the recessed bearing I92. The purpose of thus removing tube 95 is to gain access to the photoelectric cell I96 inside of tube 96, when it is necessary to replace cell I96. When tube 95 is to be replaced in position, its right 'end can be guided through ring 95 by supporting the cylinder 93 in proper position by hand, access being had to the cylinder .93 through. the bQttom of easing 2 which is open. Cell I86 is supported Ina usual socket Iill mounted on a cup-shaped support I68 removably fitting inside of tube 96 and held in place by screws such as I99. The cylinder 33 has a plurality of peripheral grooves such as indicated at H6 in Fig. 2, three being shown, and for each groove there is a spring stripping finger III as shown in Fig. 1, one end of the stripper being secured to the inside or" wall 8 as indicated at H2, and its other end resiliently riding in a groove as indicated at H3, to strip oil the master 5 and guide it to the outlet 9. The master 5 is held on the cylinder 93 by suitable pressure rollers or pad rollers indicated at II4 and H5 in Fig. 1, and also by a pressure plate I85 having a 2' spring not shown. Plate I85 forms the lagging edge of slit 88.

Clutch cntr0Z.-The photo-cell I06 which is inside of tube 99, as shown in Figs. 1 and 2, and the photo-cell 31 which is outside of wall 34 as shown in Fig. 3, are connected in a bridge circuit II6, as shown in Fig. 9. These photo-cells are illuminated and balanced as follows: Inside of casing 2 is an inclined shelf Ii? supporting two foto-fiood lamps IIB and H9 each mounted in a chimney I28 and l2I respectively. Each chimney like I26 opens at its bottom as indicated at I22 in Fig. l and has a screen I23 over its top at the top of the casing 2, to ventilate the lamps. Each chimney has a circular opening like I24 over which is suitably supported a spherical Fresnel lens I25. The two lenses like I25 illuminate a rectilinear cylindrical Fresnel lens I 26 to uniformly illuminate the elongated slit 88 which extends the length of the cylinder 93. The lamps H8 and II 9 and their lenses I25 and I 26 have optical axes as indicated at I28 in a plane which is inclined to the optical axis plane I29 along which light is reflected from the master material at slit 88 to the film I39 in magazine II. On the optical axis plane I28, inside of cylinder 93 and outside of tube 96 is an inclined mirror I3I which reflects radiation, which may or may not be visible rays, from lamps H8 and H9 through opening I32 in tube 96 to cell I86, assuming there is no paper or other master material on the drum 7. Light or other radiation from lamp II8 passes through an opening I33, see Fig. 3 in wall 34, to excite cell 31. The amount of light passing through opening i33 is adjusted by suitable shutters I34 and held in adjusted position by means such as screws like I36. The shutters I34 and E35 are adjusted to balance the cells 37 and 583 which are in opposite arms of bridge II 6.

Bridge II6 is energized by current from a dou- V ble rectifier 36. Cells 31 and I93 remained balanced when there is no master material on drum "I, regardless of whether the light intensity of lamps H8 and H9 is high or low and regardless of fluctuations in the lamp intensity due. to fluc-- tuations in the line voltage, as both cells areexcited by the same radiant source. When master material such as a sheet of paper, regardless of whether the paper is opaque or whether it is translucent, is fed to the drum I, when the leading edge of such material arrives at slit 88, it upsets the balance between the cells 31 and I86, thereby putting a potential on the input circuit of tube 38 which may be a thyratron amplifier, to operate relay 39. Before relay 39 operates, with the main line switch 4! closed, lamps H8 and H9 are illuminated at low intensity as they are connected in series through the back contacts I 31, it? of relay 39, over an obvious circuit as shown in Fig. 9. When relay 39 operates, lamps H8 and '9 are illuminated at normal intensity as they are connected in parallel over the front contacts I38 and I39 to the line I40. Also solenoid 5I is now connected to line 440 through the front contact I4I of relay 39, assuming that switch I42 is closed. Switch I42 is a magazine safety switch which is closed so long as there is film on the supply reel I5. Switch I42 has a contact I43 on the inner side of wall 86 which is broken by a contact I44 on follower I68 when follower I69 drops to a position where all of the film I39 has been fed oil of the film supply I 5. When solenoid 5| is energized as above described, it operates clutch 35 to connect drive sprocket 88 to motor 3I, to drive the film I38. Red lamp 49 is connected across solenoid 5| and is illuminated when solenoid 5! is actuated and is extinguished when solenoid is not energized. As solenoid 5i operates the clutch 35 to drive the film I 38, when lamp 49 is on, it indicates that the film I38 is being propelled, and as solenoid 5! is energized only when bridge II6 is upset due to the presence of a master on drum I, when lamp 49 is lit it shows that the micro-film camera I is in operation, printing or photographing on to film I 36 subject matter from master 5. Assuming there is suificient amount of film I38 on the supply reel I5, lamp 49 is extinguished when the trailing edge of the master 5 passes the slit 88, thereby restoring the balance of the bridge I I6, to de-energize relay 39. Whether the trailing edge of master 5 has passed slit 88 or not, if the film supply I 5 has been exhausted, switch I42 will,

operate to extinguish lamp 49. In this event, the particular master 5 would haveto be photographed again after magazine II had been loaded with fresh film. The tubes 38 to 38 are R. C. A. tubes and the type numbers are as follows: 38 is No. 6H6; 3'! and I83 are No. 929; 38 is No. 2050. The filament circuit for the indirectly heated cathodes of tubes 36 and 38 is indicated at I45 in Fig. 9 and the values of the resistances and condensers in bridge circuit II6 are indicated on Fig. 9, the condenser values being in m. f. The green light 46 is on while the main switch 4i is closed, motor 3| operating and lamps IIS and I I9 being connected in series, with camera magazine II idle, until master 5 is fed to drum 2. Switch is normally open and may be manually closed at the start to wind up the leader of exposed end of film I38 so as to bring fresh film infront of the printing slit 2i. Closing switch 59 energizes solenoid 5| over an obvious circuit and lights the pilot lamp 49 at the same time.

Adjustable hack focus.At the time the apparatus is manufactured and tested, as above described, it is necessary to compensate for the fact that different objectives 25 have different focal lengths. This is taken into account by providing a simple arrangement for adjusting both the-.frontand the back focal lengths. The back focal length is adjusted by providing an adjustable stop I46, see Fig. 4, to limit the insertion of magazine II into its compartment I5, by the amount necessary to bring the film I36 behind slit 2I in focus. As shown in Fig. i, the stop I43 may comprise a bolt I4! extending into the rear wall 22 of compartment I8, the bolt having two lock nuts I48 and I49 on opposite sides of wall 22. As shown in Fig. 2, the wall 89 of magazine II has a sleeve I 58 which engages the inner end I 5I of bolt I4! to limit the insertion of magazine II to the proper amount. The magazine II is held in its innermost position against the bolt end I5I, by means of a spring I52 on the inner side of door I2. A suitable latch I53 holds the door I2 closed. Door I2 has a hinge as indicated at I54 on the top cover 29.

Adjustable front focal length and image directz'0n.The recording sprocket 86and the master drum 1 both rotate in the same direction, that is clockwise as seen in Fig. 1. Assuming the top of a letter or the like is inserted in the inlet 6, the reading matter will appear upside down at slit This image is inverted by the two mirrors I55 and 556 so that the image is erect on leaving mirror I56 and is again inverted by lens 25 so that the image travels in the same direction as film I35 behind slit H. The mirrors I55 and I55 are spaced apart the same distance as the axes of drums I and 86, and those mirrors are set at forty-five degrees facing each other so that the optical axis I29 from slit 88 to mirror I55 is substantially parallel to the optical axis I58 from mirror I56 to slit 2 I. Mirror I55 is about as long as slit 88 whereas mirror I56 is somewhat shorter. These mirrors I55 and I56 are suitably mounted on a bracket I6I having similar side fianges, one of which is shown at I52 in Fig. 1. Flange I62 has a vertical slot I63 in which rides a pin I 64 on the upper end of a lever arm I65 pivoted at its central portion as indicated at- I16 to a similar lever I66. The lower end of lever I55 is pivotally connected to the wall 34 as indicated at I51 while the lower end of lever I66 is pivotally connected to the flange I52 as indicated at I68. The levers I55 and I 66 comprise a parallel link motion or lazy tong, the upper end of lever I66 as shown in Fig. 6 having a bearing support on a pin Ill which rides in a vertical slot I12 in the side wall 35. Slot I12 is enclosed by the cover as shown in Fig. 3, while bracket I62 is housed in the casing 2. Pin I1I is at the end of a rod I13, the other end of rod I13 having pin like I1I forming an axle for the upper end of the lever like 555. A slot not shown, like I12, is provided inside the other side wall. Between the side walls, one of which is indicated at 35 in Fig. 6 is a shelf I'M having soldered thereto a nut I15 for a bolt I16 rotatably mounted in the central portion of rod I13 as indicated at I11. A compression spring I18 on the bolt I16 maintains the rod I13 against the head of bolt 16 which may be threaded into or out of nut I to raise or lower the upper ends of levers like I66 and move bracket I5! and the mirrors I55 and I55 carried thereby, to the right or left, as seen in Fig. 1, to vary the focal length from slit 88 to the objective 25. After this adjustment is made, bolt I16 may be locked into position by alock nut I19.

Lamp ventilation-The casing 2 may have feet as indicated at I86 in Fig. 1 to support casing 2 with its open bottom I8I above the level horizontal support on which the micro-film camera I rests, whereby a current of air may enter the open bottom IBI and ventilate the lamps IE8 and H9 through their chimneys I20 and I 2!.

Operation.-While the operation will be apparcnt from the above description, it may be summarized in general as comprising the following steps: (1) Insert a loaded magazine II in its compartment It; (2) Close main line switch I1 and wait about twenty seconds for the tube filaments in circuit I55 and the flood lamps IIB and H9 to heat up; (3) Close switch 59 to expel exposed film; (a) Insert the paper or master 5 to be microfilmed; (5) At the close of the day or at the end of the operation, open main line switch 41.

The invention provides safeguards through the provision of the signal lamps referred to above and through preventing the operation of the machine unless the following conditions are fulfilled, namely, the film magazine in place, the film magazine loaded with fresh film, and both projection lamps functioning. These safeguards make it impossible to operate the camera unless it is functioning properly.

GeneraZ.While the invention has been de-- scribed as a micro-film camera, it may also be described as a projection printer. Various features of the invention may be used with other types of cameras or with other types of continuous projection printers. Various modifications may be made in the invention without departing from the spirit of the following claims.

I claim:

1. A micro-film camera having a film feeding means, a motor for driving said means, and an electrically controlled clutch between said motor and means, positioning means for copy material, a photosensitive device adjacent said positioning means, a source of light for energizing said device, said device being arranged to control operation of said clutch and being so positioned that copy material on said positioning means will intercept light from said source whereby said device will operate said clutch to establish a driving connection between said motor and film feeding means, said source of light being also arranged to illuminate said copy material when on said positioning means and a film supply means for said camera, a film actuated switch, a signal light, said signal light being arranged in a circuit under the control of both said photosensitive means and said film actuated switch whereby said light is energized when copy material is on said positioning means and film is in said supply means but extinguished in the absence of film from said supply means or of copy material from said positioning means.

2. A micro-film camera having a film feeding means, a motor for driving said means, and an electrically controlled clutch between said motor and means, positioning means for copy material, a photosensitive device adjacent said positioning means, a source of light for energizing said device, said device being arranged to control operation of said clutch and being so positioned that copy material on said positioning means will intercept light from said source whereby said device will operate said clutch to establish a driving connection between said motor and film feeding means, said source of light being also arranged to illuminate said copy material when on said ,positioning means, said positioning means being a translucent cylinder about which said copy material is guided, said photosensitive device being positioned within said cylinder.

3. A micro-film camera comprising, a rotatable drum for'supporting and moving copy material, a shaft parallel to said drum, a friction roller on said shaft and engaging the periphery of said drum whereby to drive said drum in rotation and hold copy material thereagainst, a camera arranged to photograph copy material on said drum, said camera including a movable film support, motor means connected to one end of said shaft, and disconnectable drive means extending from the other end of said shaft to said movable film support, detecting means for detecting the presence or absence of copy material on said drum and operable, in the absence of such material, to disconnect said driving means between the said other end of said shaft and the said movable film support, said detecting means comprises a photosensitive element, a light source arranged to illuminate copy material on said drum, said photosensitive element being arranged to receive light from said source and thereby operate to disconnect said driving means, the arrangement being such that copy material on said drum will intercept light directed from said source toward said photosensitive element, said drum comprising a hollow cylinder of light-transmitting material, said photosensitive element being positioned in said cylinder.

EMMANUEL BERLANT.

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